Mouse controlled. There are three rows of coloured marbles across the top of the screen, sorted randomly. At the bottom of the screen you will find one coloured marble in the centre and another to the far left. On the far right is a Recycle symbol.
The idea of the game is to destroy all the coloured marbles at the top of the screen. To do this you will find that you can shoot the bottom centre marble towards the aimer which is a cross in a circle controlled by mouse movement. When two marbles of the same colour collide they will break and the pieces will fall to the floor of the game just above where you shoot your marbles from. Place the aimer over a marble of the same colour in the top rows and click on it. Your shooter marble will travel towards it. If it hits a marble of another colour on the way it will bounce off and break without scoring any points. Hit another marble of the same colour and score 10 points. When the marbles in the top rows break their broken pieces can strike other marbles of the same colour next to them, in a line or diagonally, and cause them to break too, scoring 10 points each time. You can also cause the shooter marble to bounce off the left, right and top walls of the game. You may be able to get awkward marbles this way.
To makes things more difficult, the three rows of marbles will travel downwards during the game. When they reach the floor or debris of broken marbles, the game is over. In each level the speed at which the marbles travel downwards gets slightly faster up to Level 9, which is about as fast as they get.
The marble on the left of the screen is the next one that will move to the centre to become the shooter marble. If you need a particular colour, you will then see by this marble when it's going to arrive. The recycle symbol on the right is to use when you can't see any other marbles of the same colour to hit easily or at all. Click on the recycle symbol and your shooter marble will be transported to a row above the moving top marbles. You can then pick up an extra 10 points later on when you have destroyed the other three rows. You can recycle marbles when you like but the maximum number in play at any one time is 62. The number of marbles in play is shown in the bottom centre of the screen. Your score is shown on the bottom left and the current level on the bottom right.
If you find that the early rounds are a little too slow for you, you could try playing tactically by recycling as many marbles as you can to the top rows, thus adding more points to your score at the end of the level.
If you destroy all the marbles then you will be shown a button to click to move on to the next level. There is no physical limit to the number of levels. When the game is over you will be shown a button to click to add any high score you might have.